In recent years, electro-optic displays of a new system having low electric power consumption and high visibility have been proposed and are being applied to electronic papers and the like. For example, an electrophoresis system is a system in which an image is displayed by impressing an electric field to a layer prepared by dispersing plural microcapsules including an oil based solvent and colored electrophoretic particles in a binder and thinly coating the dispersion and transferring the colored electrophoretic particles. In addition, an electrowetting system is a system in which an image is displayed by disposing plural pixels filled with two phases of an aqueous medium and an oil based coloring ink on a substrate, controlling the affinity at an interface between the aqueous medium and the oil based coloring ink for every pixel by ON-OFF of voltage impression, and spreading or gathering the oil based coloring ink on the substrate, and this system has a high response rate as compared with the electrophoresis system (Non-Patent Document 1).
Dyes to be used for such oil based inks of displays are required to have high solubility, high absorption coefficient, and high durability such as light resistance, etc. Patent Document 1 exemplifies Oil Blue N, Solvent Green, Sudan Red, and Sudan Black as dyes to be used for oil based inks of displays of an electrowetting system. Patent Document 2 discloses specified anthraquinone based dyes as a dye for dye transfer type thermal transfer recording.